Promise
by Call Me Babykins
Summary: After a so-close-to-unsuccessful-you-can-taste-it hunt leaves the boys reeling, Sam takes what he needs. Power play themes. PWP. Established Wincest. Part of my First Times compilation.
1. Disclaimer

The following is intended for mature audiences. Discretion is advised. Contains incest, barebacking, and size kink, and mild power play themes.

Supernatural and its characters belong to Eric Kripke.


	2. Chapter 1

Sam's heart was still pounding—Dean could feel it resounding through every point of contact when Sam pressed against him, drawing him into a deep kiss. Sam was scared still, even though the shot aimed at Dean's head missed, even though they were back in the hotel, back in each other's arms.

Dean could feel the fear still rolling off of Sam in waves. If he knew something he could say or do that would make it better, would bring Sam back to the present, he would, but this had happened enough times for both of them to know that there was no magic remedy. So Dean murmured the wholly inadequate, familiar phrase, the first one that he could remember ever saying, "It's okay, Sammy," and let himself become pliant, malleable in Sam's hands.

It was obvious the moment Sam caught on to what Dean was doing. Sam's movement, desperate and aggressive, slowed. He sighed, running his nose along Dean's jaw, his breath hot on Dean's neck.

Sam pushed off Dean's jacket, peppering Dean's skin with kisses as he stripped Dean piece by piece. Dean made no move to help, kissing Sam tenderly when Sam's mouth was near enough, brushing his fingers lightly over whatever part of Sam's skin they came in contact with, but otherwise allowing Sam complete control over his body.

Sam fumbled over his belt buckle for a moment, finally tugging Dean's jeans and boxers down over his ass, exposing Dean. It was uncomfortable, jeans pooling around the tops of his boots and Sam still fully clothed, but Dean didn't move to cover himself. Sam needed this; Sam needed him like this.

Sam towered over him, pressing tiny kisses to Dean's hairline, hands spanning his chest. Dean stroked the line of buttons on Sam's plaid shirt. His skin was on fire, Dean wanted nothing more than to tear Sam's shirt open and bend him over. By now he would've had Sam naked, prepped, and be fucking him on all fours on the floor if he had his way; he itched to move faster, but reined in the urge.

Sam trailed one of his hands down Dean's chest, resting it in the hollow of his hip. Sam's proximity and body heat made Dean's cock twitch, skin on fire. Finally Sam pushed him backward until he was sitting on the end of one of the hotel beds and knelt in front of him.

Though Sam never looked up, never met his eyes, the tenderness and the intimacy Dean felt as Sam removed his boots and socks, finally tugging his pants off completely, was nearly tangible, thick and heavy in the air. There, with Sam on his knees between his spread thighs, Dean expected them to return to their usual M.O.—Dean fucking Sam's mouth before slamming him down to fuck him properly—but Sam stilled, reverently caressing Dean's inner thighs before reaching for the lube and slicking up Dean's cock.

He stood suddenly and pressed another hasty kiss to Dean's mouth, still jacking Dean's cock with a grip almost painfully slow and tight. "Lie down on your back," he breathed against Dean's mouth.

Dean did as he was told, heart suddenly standing in his throat. This was new; even in a fight, Sam has never had Dean on his back for long. The sheer submissiveness of it made Dean dizzy.

Sam stripped off his own clothes with the same hurried desperation with which he first kissed Dean. It was reassuring to see that under this eerie, unfamiliar meticulousness Sam was still sex-eager and hungry. It made Dean want to smile, but he could do little more than moan as Sam got onto the bed and straddled him, their cocks pressed tight together between their bodies.

Sam was in complete control and, though they had done this more times than Dean could count, he couldn't remember a time when he let Sam do this. Of course Sam had been on top before, but not for a long time, and Dean found himself struggling to remember when Sam got so big, so fucking commanding. It was nigh impossible to reconcile the image he had of his blushing teenage brother, shy and sensitive like no one else Dean had ever been with, with the monster of a man whose weight had settled over him, hips pumping agonizingly slow and massive hands angling his head to direct and deepen their kiss.

Sam was laid out on top of him, every inch of their bodies pressed against each other, overwhelmingly hot and too heavy, and Sam was tongue-fucking him so deep Dean was sure he was going to choke.

Sam ground his hips down against Dean, his every movement languid as though he had all the time in the world. And, really, if Sam wanted to keep Dean pinned there forever he probably could. The realization knocked the breath out of Dean:_ fuck_, Sam really was big enough to do whatever he wanted. The knowledge was almost terrifying, but it was _Sam_ and that twisted the idea of being trapped under an enormous, muscled body with absolutely no control into something so desirable that Dean gasped. Sam inhaled, as if he was taking the noise straight from Dean's mouth into his lungs, sucking Dean's tongue into his mouth as if it were Dean's cock.

Dean grabbed Sam's thighs, nails digging deep into the flesh. He couldn't breathe, but he wasn't sure he wanted to anymore. If not breathing meant feeling Sam connected to him, chest to chest, cocks dragging together, mouths hot and open, he might be content never to breathe again.

Sam pulled away slightly, laying a chaste kiss to Dean's chin. Dean watched, fingers still tensed around the muscles of Sam's thighs as Sam sat up. When had his little brother grown so damn tall? The expanse of Sam's torso seemed to stretch for miles above Dean, glistening with their combined sweat in the dim light.

For a heart-stopping second Dean was certain that Sam was going to spread his legs and fuck him raw—Sam's eyes were dark with arousal, still sharp with fear—but Sam moved up Dean's body, still straddling him, until Dean's slick cock was pressed between his ass cheeks.

Even though they'd fucked that morning, there was no way Sam was open enough to take him, but Dean didn't protest as Sam raised himself up on his knees and guided Dean's cock into his body. This was Sam's show.

Sam hissed, head thrown back, as he sank down. He was tight—too tight. Dean dug his fingers deeper into the meat of Sam's thighs. Sam had to be hurting—the searing pressure around Dean's cock was almost painful.

Sam paused, the muscles of his ass contracting rapidly, involuntarily. He clenched his fists against Dean's chest, face screwed up in pain. Dean reached up, stroking Sam's hip.

"Hey, slow down, Sammy,"

Sam didn't seem to hear him. The moment his breathing evened out, Sam straightened his back and sank lower, taking Dean in until he was resting flush against Dean's body. Dean had never pegged Sam as a pain slut but, damn, it looked good on him.

Sam rocked his hips experimentally and Dean thrashed, grabbing Sam's hips to try and keep him still. Sam was impossibly, painfully tight and fucking heavy on top of him. The sensation was too intense.

"_Fuck_, Sammy,"

The smallest ghost of a smile flitted across Sam's face before he lifted himself and slammed home.

"Goddamn, mother_fuck_, Sam," Dean bolted up, gripping Sam's hips tighter as if he could stop him.

Then Sam grinned and Dean would be damned if it wasn't the most terrifying and exhilarating thing he had ever seen. Sam shoved Dean back flat against the bed, rubbing his palms rough and fast over Dean's nipples, eliciting a moan as the sensation sent jolts to Dean's groin.

"_Sam!_"

Sam huffed a little laugh, slowing to roll the hardened nubs between his fingers. "Like that, Dean?"

Sam liked having Dean helpless, at his mercy, Dean could see it in how broad Sam's smile was, how shallow his breath had gotten.

"Shit, Sammy, so fucking tight—can't—"

"You don't have to. Lay back and let me."

Sam lifted himself up again, bracing his hands beneath Dean's pectorals, and swiveled his hips, looking down as though this were an experiment and he intended to observe and record all of the results. Seemingly satisfied with the resulting gasp, Sam leaned in for one more open-mouthed kiss before he sat up tall and _rode_ Dean.

"Fuck, Sammy, ah _shit_! C'mon, ride me, motherfucking _bitch_, fuck, Sam don't stop! _Fuck_," Dean couldn't control the words coming out of his mouth any more than his hands on Sam's hips slowed his brother down.

All he could see was Sam's cock—as enormous as the rest of him, the head red and dripping precome—bouncing above him as Sam circled his hips, slamming down hard. The pressure of Sam's body—pelvis to hips and hands on his ribs—was crushing. When had Sam become this fucking force of nature?

Sam was panting out words, but it took Dean a moment before he understood Sam's breathless pleading, "Look at me—Dean, wanna see, look at me, look …"

Dean looked up into Sam's face, his vision a little unfocused, shaking with every jarring thrust against the bed. Sam's eyes were wide, wet with unconscious tears, tracking every change in Dean's face. He looked open wide—vulnerable and scared and high off of every sensation like Dean had never seen him.

"Fuck, baby boy, love you so much," Dean reached up as far as he could on Sam's massive chest and dragged his fingers down. He'd intended to jerk Sam off, but before he even reached Sam's cock, Sam came untouched. Shuddering, he leaned down to kiss Dean again, pumping his hips faster as his muscles clenched and he spurted hot between their bodies.

His thrusts slowed as his orgasm faded. Sam angled Dean's head again, fucking his mouth with his tongue, purposefully contracting his muscles at the bottom of every stroke, until Dean was coming, crying out Sam's name, hands—no longer carefully controlled—leaving deep scratches all over Sam's body. And Sam took all of it: kissing the sounds from Dean's mouth, arching into his fingers, keeping Dean's cock seated deep inside him as it pulsed, filling him up.

Sam gentled as Dean came down, laying gentle kisses on his upper lip, rubbing his thumbs along the contours of Dean's face.

It was nearly inaudible—Dean almost missed it—but while he lay still, and fucking heavy, on Dean's chest Sam breathed, "Don't you ever fucking leave me."

And Dean kissed the patch of Sam's skin which was nearest him and mouthed, "I promise."


End file.
